Performance Analysis of RIS-Assisted Spectrum Sharing Systems

TL;DR

This paper analyzes the performance of a RIS-assisted spectrum sharing system, deriving new analytical expressions for key metrics like outage probability and capacity under fading conditions, and validates findings with simulations.

Contribution

It introduces novel analytical expressions for SNR distribution and performance metrics in RIS-assisted spectrum sharing systems under fading environments.

Findings

Derived exact expressions for outage probability, capacity, and error rate.

Provided asymptotic performance expressions at high peak power.

Confirmed theoretical results with extensive Monte-Carlo simulations.

Abstract

We propose a reconfigurable intelligent surface (RIS)-assisted underlay spectrum sharing system, in which a RIS-assisted secondary network shares the spectrum licensed for a primary network. The secondary network consists of a secondary source (SS), an RIS, and a secondary destination (SD), operating in a Rician fading environment. We study the performance of the secondary network while considering a peak power constraint at the SS and an interference power constraint at the primary receiver (PR). Initially, we characterize the statistics of the signal-to-noise ratio (SNR) of the RIS-assisted secondary network by deriving novel analytical expressions for the cumulative distribution function (CDF) and probability density function (PDF) in terms of the incomplete H-function. Building upon the SNR statistics, we analyze the outage probability, ergodic capacity, and average bit error rate, subsequently deriving novel exact expressions for these performance measures. Furthermore, we obtain novel asymptotic expressions for the performance measures of interest when the peak power of the SS is high. Finally, we conduct exhaustive Monte-Carlo simulations to confirm the correctness of our theoretical analysis.